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Calkinsiidae
''Calkinsia'' is a monotypic genus of excavates comprising the single species ''Calkinsia aurea''. It lives in low-oxygen seafloor environments. It is not classified in any of the three well-known groups of the Euglenozoa (Kinetoplastida, Euglenida or Diplonemida), but is placed in its own group, the Symbiontida (along with some DNA sequences which were found in marine environments but not identified with known organisms). Some authors have classified ''Calkinsia'' alongside ''Postgaardi'', but ''Postgaardi'' has not been studied well enough to test this hypothesis. The genus name of ''Calkinsia'' is in honour of Gary Nathan Calkins (1869 – 1943), who was an American protozoologist and a professor at Columbia University Columbia University in the City of New York, commonly referred to as Columbia University, is a Private university, private Ivy League research university in New York City. Established in 1754 as King's College on the grounds of Trinity Churc .... He w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Euglenozoa Genera
Euglenozoa are a large group of flagellate Discoba. They include a variety of common free-living species, as well as a few important parasites, some of which infect humans. Euglenozoa are represented by four major groups, ''i.e.,'' Kinetoplastea, Diplonemea, Euglenida, and Symbiontida. Euglenozoa are unicellular, mostly around in size, although some euglenids get up to long. Structure Most euglenozoa have two flagella, which are inserted parallel to one another in an apical or subapical pocket. In some these are associated with a cytostome or mouth, used to ingest bacteria or other small organisms. This is supported by one of three sets of microtubules that arise from the flagellar bases; the other two support the dorsal and ventral surfaces of the cell. Some other euglenozoa feed through absorption, and many euglenids possess chloroplasts, the only eukaryotes outside Diaphoretickes to do so without performing kleptoplasty, and so obtain energy through photosynthesis. These ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eukaryota
The eukaryotes ( ) constitute the Domain (biology), domain of Eukaryota or Eukarya, organisms whose Cell (biology), cells have a membrane-bound cell nucleus, nucleus. All animals, plants, Fungus, fungi, seaweeds, and many unicellular organisms are eukaryotes. They constitute a major group of Outline of life forms, life forms alongside the two groups of prokaryotes: the Bacteria and the Archaea. Eukaryotes represent a small minority of the number of organisms, but given their generally much larger size, their collective global biomass is much larger than that of prokaryotes. The eukaryotes emerged within the archaeal Kingdom (biology), kingdom Asgard (Archaea), Promethearchaeati and its sole phylum Promethearchaeota. This implies that there are only Two-domain system, two domains of life, Bacteria and Archaea, with eukaryotes incorporated among the Archaea. Eukaryotes first emerged during the Paleoproterozoic, likely as Flagellated cell, flagellated cells. The leading evolutiona ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Excavata
Excavata is an obsolete, extensive and diverse paraphyletic group of unicellular Eukaryota. The group was first suggested by Simpson and Patterson in 1999 and the name latinized and assigned a rank by Thomas Cavalier-Smith in 2002. It contains a variety of free-living and symbiotic protists, and includes some important parasites of humans such as ''Giardia'' and '' Trichomonas''. Excavates were formerly considered to be included in the now- obsolete Protista kingdom. They were distinguished from other lineages based on electron-microscopic information about how the cells are arranged (they have a distinctive ultrastructural identity). They are considered to be a basal flagellate lineage. On the basis of phylogenomic analyses, the group was shown to contain three widely separated eukaryote groups, the discobids, metamonads, and malawimonads. A current view of the composition of the excavates is given below, indicating that the group is paraphyletic. Except for some Eugleno ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monotypic Taxon
In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of Genus, genera, the term "unispecific" or "monospecific" is sometimes preferred. In botanical nomenclature, a monotypic genus is a genus in the special case where a genus and a single species are simultaneously described. Theoretical implications Monotypic taxa present several important theoretical challenges in biological classification. One key issue is known as "Gregg's Paradox": if a single species is the only member of multiple hierarchical levels (for example, being the only species in its genus, which is the only genus in its family), then each level needs a distinct definition to maintain logical structure. Otherwise, the different taxonomic ranks become effectively identical, which creates problems for organizing biological diversity in a hierarchical o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AlgaeBase
AlgaeBase is a global species database of information on all groups of algae, both seaweed, marine and freshwater algae, freshwater, as well as sea-grass. History AlgaeBase began in March 1996, founded by Michael D. Guiry, Michael Guiry. Text was copied from this source, which is available under aAttribution 4.0 International (CC BY 4.0)licence. (Sehere. By 2005, the database contained about 65,000 names. In 2013, AlgaeBase and the Flanders Marine Institute (VLIZ) signed an end-user license agreement regarding the intellectual property, Electronic Intellectual Property of AlgaeBase. This allows the World Register of Marine Species (WoRMS) to include taxonomic names of algae in WoRMS, thereby allowing WoRMS, as part of the Aphia database, to make its overview of all described marine species more complete. Synchronisation of the AlgaeBase data with Aphia and WoRMS was undertaken manually until March 2015, but this was very time-consuming, so an online application was developed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kinetoplastida
Kinetoplastida (or Kinetoplastea, as a class) is a group of flagellated protists belonging to the phylum Euglenozoa, and characterised by the presence of a distinctive organelle called the kinetoplast (hence the name), a granule containing a large mass of DNA. The group includes a number of parasites responsible for serious diseases in humans and other animals, as well as various forms found in soil and aquatic environments. The organisms are commonly referred to as "kinetoplastids" or "kinetoplasts". The kinetoplastids were first defined by Bronislaw M. Honigberg in 1963 as the members of the flagellated protozoans. They are traditionally divided into the biflagellate Bodonidae and uniflagellate Trypanosomatidae; the former appears to be paraphyletic to the latter. One family of kinetoplastids, the trypanosomatids, is notable as it includes several genera which are exclusively parasitic. ''Bodo'' is a typical genus within kinetoplastida, which also includes various common f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diplonemea
Diplonemidae is a family of biflagellated unicellular protists that may be among the more diverse and common groups of planktonic organisms in the ocean. Although this family is currently made up of three named genera; '' Diplonema'', '' Rhynchopus'', and '' Hemistasia'', there likely exist thousands of still unnamed genera. Organisms are generally colourless and oblong in shape, with two flagella emerging from a subapical pocket. They possess a large mitochondrial genome composed of fragmented linear DNA. These non-coding sequences must be massively trans-spliced, making it one of the most complicated post-transcriptional editing process known to eukaryotes. Etymology The word “Diplonemidae” come from the Greek words ‘diplo’, meaning two, and ‘nemat’, meaning thread. Together, Diplonemidae roughly translates to ‘two threads’, likely referring to the characteristic two flagella of the organism. History Primary studies done in the 1900s by Griessmann and Skuja h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Postgaardi
''Postgaardi mariagerensis'' is a species of single-celled eukaryote in the Euglenozoa Euglenozoa are a large group of flagellate Discoba. They include a variety of common free-living species, as well as a few important parasites, some of which infect humans. Euglenozoa are represented by four major groups, ''i.e.,'' Kinetoplastea, .... Some have classified it in a class called Postgaardea along with '' Calkinsia'', but as of 2009, ''Postgaardi'' is not well enough known to confidently determine its relationship with other organisms in the Euglenozoa. Both it and ''Calkinsia'' do live in low oxygen environments and are covered with bacteria which live on their surface. Species The only species in the genus ''Postgaardi'' is ''P. mariagerensis''. References Further reading * * Euglenozoa genera Monotypic eukaryote genera {{Excavata-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gary Nathan Calkins
Gary Nathan Calkins (18 January 1869 – 4 January 1943) was an American protozoologist and a professor at Columbia University. He wrote several landmark textbooks on the biology of the protozoa. He described conjugation in '' Paramoecium'' and in his taxonomic approach separated chlorophyll containing flagellates from other protists. Calkins was born in Valparaiso, Indiana to John Wesley Calkins and Emma Frisbie Smith He graduated from Massachusetts Institute of Technology in 1890 and taught for a while. He worked briefly at the Marine Biological Laboratory, Woods Hole, and then continued further studies at Columbia University and obtained a Ph.D. in 1897. His influences at Columbia included Henry Fairfield Osborn. He rose to professor of zoology in 1904 which was later renamed as professor of protozoology. He worked at Columbia University for most of his life retiring as an emeritus professor in 1939. He also took an interest in statistics and worked as a consultant in cancer re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protozoologist
Protistology is a scientific discipline devoted to the study of protists, a highly diverse group of eukaryotic organisms. All eukaryotes apart from animals, plants and fungi are considered protists. Its field of study therefore overlaps with the more traditional disciplines of phycology, mycology, and protozoology, just as protists embrace mostly unicellular organisms described as algae, some organisms regarded previously as primitive fungi, and protozoa ("animal" motile protists lacking chloroplasts). They are a paraphyletic group with very diverse morphologies and lifestyles. Their sizes range from unicellular picoeukaryotes only a few micrometres in diameter to multicellular marine algae several metres long. History The history of the study of protists has its origins in the 17th century. Since the beginning, the study of protists has been intimately linked to developments in microscopy, which have allowed important advances in the understanding of these organisms due t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
